Field of the Invention
The present invention relates generally to a system and method for producing a spool having a continuous fabric strip wound thereupon, and more particularly to a system and method for producing an extended length strip of pile fabric made from a plurality of seamed standard lengths of the pile fabric, the extended length strip of pile fabric being spirally wound upon a hollow core with consecutive windings of the fabric strip being located close adjacent each other, and with consecutive rows of the fabric strip overlaying each other on the hollow core.
The two inventions which have had the greatest impact on paint application are the invention of the paint roller in the 1930""s and the development of water-based paint in the late 1940""s. While water-based paints are easy to mix, apply, and clean up, there is little doubt that the paint roller has been the greatest single time saving factor in the paint application process, allowing large surfaces to be painted with a uniform coat of paint quickly and easily. Typically, paint rollers are comprised of two components, namely a handle assembly and a paint roller cover for installation onto the handle assembly.
The handle assembly consists of a grip member having a generally L-shaped metal frame extending therefrom, with the free end of the metal frame having a rotatable support for a pain roller cover mounted thereon. The paint roller cover consists of a thin, hollow cylindrical core which fits upon the rotatable support of the handle, with a plush fabric being secured to the outer diameter of the paint roller cover. The core may be made of either cardboard or plastic material, with which material is used for the core generally being determined based upon the selling price of the paint roller cover. The plush fabric is typically applied as a strip which is spirally wound onto the outer surface of the core, and which may be secured either by using adhesive or by the application of heat during the manufacturing process to bond the fabric strip to the core. In either event, adjacent windings of the fabric strip are located close adjacent each other, to provide the appearance of a single continuous plush fabric covering on the core.
Typically, the plush fabric is a dense knitted pile fabric, which is manufactured in segments which are approximately sixty inches wide by thirty to fifty yards long (depending on fabric weight). As these segments are taken off the manufacturing line, they are slit into two and seven-eighths inch wide strips, which are wound into rolls which are then provided to the paint roller cover manufacturer for use in the manufacture of paint roller covers. Each of the sixty inches wide by thirty to fifty yard long segments will yield twenty such rolls, with each roll being thirty to fifty yards long.
The knitted pile fabric may be knitted from natural fibers such as wool or mohair, synthetic fibers such as polyester, acrylic, nylon, or rayon, or from a blend of natural and synthetic fibers. The knitting is typically performed on a circular sliver knitting machine, which produces a tubular knitted fabric backing with a knit-in pile. The backing is typically made of synthetic yarns, with the pile being made of a desired natural or synthetic fiber, or a blend of different fibers. The tubular knitted pile fabric is then slit to produce an extended segment of fabric which is typically sixty inches wide by thirty to fifty yards long, as mentioned above.
The knitted pile fabric segment is then tensioned longitudinally and transversely, and is then back coated (on the non-pile side of the backing) with a stabilized coating composition such as a clear acrylic polymer. The coating composition which is coated onto the non-pile side of the backing is then processed, typically by heat, to produce such a stabilized knitted pile fabric segment. The heating operation dries and bonds the coating composition to the backing, producing a fabric which is essentially lint-free.
The coated knitted pile fabric can then be subjected to a shearing operation to achieve a uniform pile length, with the sheared fibers being removed by vacuum, electrostatically, or by any other known removal technique. The pile density, the nap length, and the stiffness of the fibers are varied based upon customer specifications and the particular characteristics of the paint roller cover which are desired.
The coated, sheared knitted pile fabric segment is then slit into a plurality of two and seven-eighths inch wide knitted pile fabric strips, of which there are typically twenty for a sixty inch wide fabric segment. The knitted pile fabric strips are rolled onto a core to produce twenty rolls of knitted pile fabric strips, each of which is thirty to fifty yards long. In the past, these eighty foot long rolls of knitted pile fabric strips would then be shipped to a paint roller cover manufacturer.
The paint roller cover manufacturer manufactures the paint roller covers by using a hollow cylindrical core made of cardboard or thermoplastic material which has the knitted pile fabric strip spirally wound around the core. The knitted pile fabric strip may be retained on the core using either an adhesive or by thermally bonding the knitted pile fabric strip in place on a thermoplastic cover. For examples of this manufacturing process see U.S. Pat. No. 5,694,688, to Musch et al., or U.S. Pat. No. 5,614,047, to Garcia.
It will be appreciated by those knowledgeable about the manufacturing of paint roller covers that one of the biggest inefficiencies in the manufacturing process is the necessity to halt the winding operation whenever the end of a segment of the knitted pile fabric strip is reached. A new knitted pile fabric strip must then be either started on the winding machine, or the new knitted pile fabric strip must be seamed to the old knitted pile fabric strip. This takes substantial manual labor, and increased the paint roller cover manufacturer""s cost of manufacturing.
It is accordingly the primary objective of the present invention that it provide both a system and a method for the manufacture of knitted pile fabric strips of a substantially extended length for use by paint roller cover manufacturers in their manufacture of paint roller covers. It is a closely related objective that the extended length knitted pile fabric strips of the present invention function as if they were one complete knitted pile fabric strip rather than a knitted pile fabric strip assembled from a plurality of shorter knitted pile fabric strips. It is also a primary objective that the extended length knitted pile fabric strips of the present invention are supplied in an easy to use configuration which the paint roller cover manufacturers will find to be convenient in their manufacture of paint roller covers, without requiring any revision of their manufacturing processes or a substantial investment in new equipment.
It is an additional objective that the extended length knitted pile fabric strips of the present invention be manufacturable at minimal additional cost as compared to knitted pile fabric strips of conventional length. It is a further objective of the extended length knitted pile fabric strips of the present invention that they be packaged in a configuration which is convenient to ship despite the extended length of the extended length knitted pile fabric strips. It is a related objective of the present invention that the form in which the extended length knitted pile fabric strips of the present invention is stored for shipment be as compact as possible to thereby require the minimum volume of packaging for shipment.
The apparatus used by the system and method of the present invention to manufacture the extended length knitted pile fabric strips must also be of construction which is both durable and long lasting, and it should also require little or no maintenance to be provided by the user throughout its operating lifetime. In order to maximize the market appeal of the extended length knitted pile fabric strips of the present invention, the system of the present invention used to manufacture them and its cost of operation must both be as inexpensive as possible to thereby afford the knitted pile fabric strips of the present invention the broadest possible market. Finally, it is also an objective that all of the aforesaid advantages and objectives of the extended length knitted pile fabric strips of the present invention be achieved without incurring any substantial relative disadvantage.
The disadvantages and limitations of the background art discussed above are overcome by the present invention. With this invention, a plurality of rolls of standard knitted pile fabric strips are joined together at their respective contiguous ends. Each of the seaming operations is performed at a seaming station using a small strip of heat-activated seaming tape which is placed over the seam on the back sides of the contiguous knitted pile fabric strips, and then heat and pressure are applied by the seaming station to create the seam. The extended length knitted pile fabric strip is then packaged appropriately for shipping into a compact, efficient configuration which is easy to ship and easy to use.
Typically, the plush fabric is a dense knitted pile fabric, which is manufactured in segments which are approximately sixty inches wide by thirty to fifty yards long. As these segments are taken off the manufacturing line, they are slit into two and seven-eighths inch wide strips, which are wound into rolls which are then provided to the paint roller cover manufacturer for use in the manufacture of paint roller covers. Each of the sixty inches wide by thirty to fifty yards long segments will yield twenty such rolls, with each roll being thirty to fifty yards long. The rolls may be temporarily stored in a segmented temporary storage container or on a dispensing stand.
The path of the knitted pile fabric strips goes from the storage container or dispensing stand, through a seaming station and then to a fabric strip accumulating station. The path continues from the accumulating station to a winder station where the extended length knitted pile fabric strip is wound onto a core which is typically a hollow cylindrical cardboard or plastic take-up core. The extended length knitted pile fabric strips is wound to produce a spool of knitted pile fabric strip in which the extended length knitted pile fabric strip is spirally wound on the cylindrical take-up core with consecutive windings of the extended length knitted pile fabric strip being located close adjacent each other, and with consecutive rows of the extended length knitted pile fabric strip overlaying each other on the cylindrical take-up core.
The knitted pile fabric strips are unrolled and placed into the system of the present invention, passing first through the seaming station. The seaming station is used to quickly seam together the contiguous ends of consecutive knitted pile fabric strips. The small strip of seaming tape is activated by heat, with the abutting ends of consecutive knitted pile fabric strips being placed upside-down (so the backing is facing up) with the seaming tape being placed over the abutting ends. Pressure and heat is then applied by the seaming station to activate the seaming tape, thereby joining the consecutive knitted pile fabric strips together.
The extended length knitted pile fabric strip is then drawn into the accumulator station by a motorized roller drive which is actuated by an operator to draw the remaining portion of the extended length knitted pile fabric strips into the accumulator station. The motorized roller drive is located on the top of a slide which extends downwardly at an angle, ending in an accumulation bin. Located at a location near the bottom of the slide is a first photodetector, and located higher up the slide is a second photodetector.
As the motorized roller drive brings the extended length knitted pile fabric strip into the accumulator, the accumulator bin at the bottom of the slide will fill up first, following which the extended length knitted pile fabric strip will begin to accumulate on the slide itself, from the bottom upward. Until the extended length knitted pile fabric strip begins to accumulate in the slide, both the first and the second photodetector are unobstructed. As the slide begins to fill up after the accumulator bin is full, first the first photodetector and then the second photodetector will be obstructed. The photodetectors are used to operate the winder station.
The extended length knitted pile fabric strips travels from the accumulator station to the winder station, where it first passes over a series of rollers and then onto a guide arm which feeds the extended length knitted pile fabric strip onto the cylindrical take-up core onto which it is wound. A third photodetector is located on the guide arm to detect whether or not the extended length knitted pile fabric strip is present thereupon. The winder station has large circular discs located at each end of the cylindrical take-up core.
The lateral movement of the guide arm is controlled by a first servo drive, thus controlling the position on the cylindrical take-up core onto which the extended length knitted pile fabric strips is wound. The rotation of the cylindrical take-up core is controlled by a second servo drive. By controlling the first and second servo drives, the winding of the extended length knitted pile fabric strip onto the cylindrical take-up core can be precisely controlled to produce a tight winding in which the extended length knitted pile fabric strip is spirally wound onto the cylindrical take-up core with consecutive windings of the extended length knitted pile fabric strip being located close adjacent each other, and with consecutive rows of the extended length knitted pile fabric strip overlaying each other on the cylindrical take-up core.
Thus, by operating the winder station with a computer-controlled operating system, the movement of the first and second servo drives can be coordinated to produce the desired winding operation, taking into account the physical parameters of the extended length knitted pile fabric strip. Thus, the width and thickness of the extended length knitted pile fabric strip will determine the relative operation of the first and second servos. In addition, as progressive layers of the extended length knitted pile fabric strip are wound onto the cylindrical take-up core, the relative movements of the first and second servos will also have to be varied.
The overall speed of the winding operation is controlled by the three photodetectors. As long as both the first and second photodetectors in the accumulator are obstructed by the accumulated extended length knitted pile fabric strip, the winding operation will operate at high speed. When only the first photodetector is obstructed, the winding operation will occur at a lower speed. Whenever the third photodetector is not obstructed, the winding operation will immediately stop. In the preferred embodiment, the winding operation will only occur when an operator is feeding additional seamed-together knitted pile fabric strips into the accumulator, so the third photodetector should only be unobstructed when the winding operation is complete.
Following the completion of the winding operation onto a cylindrical take-up core, apparatus unrelated to the present invention would be used to secure the extended length knitted pile fabric strip roll. One end of the apparatus supporting the cylindrical take-up core will then be retracted, allowing the extended length knitted pile fabric strip roll to be removed from the winder station. The extended length knitted pile fabric strip roll may then be packaged for delivery in a box or in plastic film, and shipped to a paint roller manufacturer.
It may therefore be seen that the present invention teaches both a system and a method for the manufacture of knitted pile fabric strips of a substantially extended length for use by paint roller cover manufacturers in their manufacture of paint roller covers. The extended length knitted pile fabric strips of the present invention function as if they were one complete knitted pile fabric strip rather than a knitted pile fabric strip assembled from a plurality of shorter knitted pile fabric strips. The extended length knitted pile fabric strips of the present invention are supplied in an easy to use configuration which the paint roller cover manufacturers will find to be convenient in their manufacture of paint roller covers, without requiring any revision of their manufacturing processes or a substantial investment in new equipment.
The extended length knitted pile fabric strips of the present invention are manufacturable at little additional cost as compared to knitted pile fabric strips of conventional length. Further, the extended length knitted pile fabric strips of the present invention are packaged in a configuration which is convenient to ship despite the extended length of the extended length knitted pile fabric strips. This shipment configuration of the extended length knitted pile fabric strips of the present invention is as compact as possible to thereby require a minimized volume of packaging for shipment.
The apparatus used by the system and method of the present invention to manufacture the extended length knitted pile fabric strips is of a construction which is both durable and long lasting, and which will require little or no maintenance to be provided by the user throughout its operating lifetime. The system of the present invention used to manufacture the extended length knitted pile fabric strips and its cost of operation are relatively inexpensive, thereby affording the extended length knitted pile fabric strips of the present invention the broadest possible market and maximizing their market appeal. Finally, all of the aforesaid advantages and objectives of the extended length knitted pile fabric strips of the present invention are achieved without incurring any substantial relative disadvantage.